The present invention relates generally a method and an apparatus for conveying objects. More specifically, the present invention relates to a method for the transfer with successive increase of speed of an object from a first conveyor driven at constant speed to a second conveyor driven at a higher constant speed.
The invention also relates to a feeding arrangement for objects delivered at regular intervals. The feeding arrangement has a first conveyor with an endless conveyor belt equipped with projecting driving elements positioned at regular intervals, and a second conveyor.
In the packaging industry, for example, frequently more or less finished packing containers are moved between different processing machines or processing stations by conveyors. To ensure an accurate coordination of the packing containers moved forward in relation to the subsequent processing machine, the conveyors are often provided with driving elements which make possible the feeding of the packing containers at predetermined intervals. In the transfer of packing containers from a slower to a faster conveyor it has been found difficult to prevent the feeding elements of the faster conveyor from damaging or deforming the packing containers, especially if the speed difference between the conveyors is great or if the packing containers are not yet finished.
It is one main object of the present invention to provide a method by which, in the packaging industry as well as in other fields, objects can be fed or transferred from a first relatively slowly moving conveyor to a second relatively fast moving conveyor without the object being deformed or damaged in some other manner and without more comprehensive, complicated and expensive technical solutions having to be adopted.
This and other objects have been achieved in accordance with the invention by a method for the transfer, with successive increase of speed, of an object from a first conveyor driven at constant speed to a second conveyor driven at a higher constant speed. The object is fed by a driving or load-contacting element positioned on the conveyor belt of the first conveyor with the element, at the end of the active portion of the first conveyor (i.e., the point at which the first conveyor ceases moving the object), being tipped forward so as to impart to the object an increase of speed before the feeding is taken over by the second conveyor. In this manner the object fed by the driving elements of the first conveyor will be accelerated to a higher speed than the basic speed of the conveyor directly before the object is transferred to and is driven by the driving elements of the second, faster conveyor. In this way the speed difference between the object and second conveyor is appreciably diminished so that the transfer can take place without jerks or impacts causing damage to the object.
A preferred embodiment of the method in accordance with invention has been given the further characteristic that the forward tipping of the driving element is effected by causing the conveying track to change its direction of movement.
A further preferred embodiment of the method in accordance with the invention has been given the further characteristic that the speed of the first conveyor plus the additional speed caused by the driving element give a combined speed which substantially corresponds to the speed of the second conveyor.
A further object of the present invention is providing an arrangement for the execution of the method in accordance with the invention.
A still further object is providing a feeding arrangement within which individual objects can be transferred from a first relatively slow conveyor to a second, faster conveyor without being damaged, deformed or detrimentally affected in some other way.
A yet further object is providing a feeding arrangement of the abovementioned type which is of a simple and reliable design and which can readily be combined with known feeding arrangements.
These and other objects have been achieved in accordance with the invention by a feeding arrangement having a first conveyor with an endless conveyor belt which is provided with projecting driving elements positioned at regular intervals and a second conveyor. The first conveyor has devices adapted for changing the orientation of the driving elements in relation to the direction of movement of the active portion of the conveyor. This design makes it possible, through a change in the orientation of the driving elements, to impart to the conveyed objects a speed during part of their movement along the active portion of the conveyor which differs from the actual speed of the conveyor. A conveyed object can be given a higher speed, for example, at the end of the active portion of the conveyor by forward tipping of the driving elements in the direction of movement. This characteristic can be made use of, for example, for imparting to the object a total speed which corresponds to the speed of the subsequent conveyor.